Solders used during a mounting step of a part such as optical part (or device) and electronic part onto an article such as printed board, film board and housing or enclosure having a circuit normally contain a large quantity of lead.
Therefore, when articles having a circuit soldered with parts by using a solder or electrical appliances comprising the same are placed outdoors as wastes after use and weather-exposed, or are ground and buried for disposal, there arises a risk of groundwater pollution by the lead contained in the solder dissolving from the wastes.
Since the use of such lead-polluted groundwater as drinking water produces hazardous effects on human body, how to treat electrical appliance junks has become a current issue of significance.
Conventionally, in order to prevent pollution by lead, the electrical appliance is disassembled primarily to collect the article having a circuit, which is contained in the appliance, and a lead containing solder is isolated in junking or recycling the electrical appliance. The remaining parts are then ground into small pieces to separate materials or are buried at a controlled dumping ground, which is designed to best obviate leakage or draining of polluted water.
In order to prevent environmental pollution by such hazardous lead, there is a demand for full recycling of lead or discontinuing the use of lead.
In order to realize a circulating economical community, it has been planned to impose a duty on every manufacturer in year 2,001 to take back used electrical appliances for return and recycling them.
Under the circumstance, however, as shown in FIG. 4, the article having a circuit using the lead containing solder and electrical appliances comprising such article (hereinafter simply referred to as “lead containing article”) on one hand, and the article having a circuit soldered with parts using a lead free solder and electrical appliances comprising such article (hereinafter simply referred to as “lead free article”) on the other hand have been manufactured and sold on the market at the same time. As a result, the two types of articles coexist on the market and are recovered as they are. The recovered articles are directly conveyed to a nearby controlled dumping ground or stabilizing dumping ground, or are treated for recycling. It is noted that the printed board and film board are contained inside the electrical appliance.
At the controlled dumping ground, the recovered articles are buried as they are without any treatment. However, at the stabilizing dumping ground, the recovered articles are treated to prevent them from scattering, flying or migrating before they are buried.
When recycled, on the other hand, the recovered articles are disassembled, and if contained, lead is isolated to make them harmless. Then, reusable materials are selected for recycling.
A method of simply burying mixed wastes of the lead containing article and the lead free article at the controlled dumping ground is easy and simple in operation but has a high construction cost, producing a problem of high treatment cost.
A method of burying the waste without recycling reusable material at a dumping ground has a problem in the aspect of effective use of resources. This method has another problem that the dumping ground itself is being saturated with supramaximal wastes.
Moreover, isolation and recovery of the solder by disassembling only the waste of the lead containing article from the mixed wastes of the lead containing article and the lead free article is not feasible and requires not only a specific instrument and an investment therefor but also a specific additional working step, which increases the treatment cost.
If the lead free article only can be recovered from among the mixed waste, it becomes possible to bury it at the stabilizing dumping ground with low construction cost by simply grinding the article. Therefore, identification and separation between the lead free article and the lead containing article among the miscellaneous recovered wastes can reduce the cost for disposal.
Under the circumstance, however, such identification takes much time and labor and has poor efficiency. Therefore, a simple means for identifying the lead free article from the lead containing article has been desired for.
In view of the above-mentioned problems, a primary object of the present invention is to provide an article having a printed board which facilitates identification whether lead is contained or not and an electrical appliance including the same.
Another object of the present invention is to provide a recycling method of the same.